1. Field of the Invention
The present invention relates generally to a nailer structure, and more particularly to an innovative shift lever switching mechanism for a trigger of a nailer.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Today, many nailers are available with a switching function for single triggering and continuous triggering in order to meet the requirements of users. The present invention aims to make a breakthrough innovation for the switching mechanism of the trigger.
Referring to FIG. 1, a typical switching mechanism comprises an eccentric regulating rod 10 and a trigger disc 20. The eccentric regulating rod 10 comprises a pressure plate 11, an eccentric rod 12 and a knob 13. The eccentric regulating rod 10 is mounted into a through groove 06 of the trigger 05. The knob 13 is normally recessed since the pressure plate 11 is supported by a return spring 14. The operator pulls out the knob 13 and then rotates the knob 13 (shown in FIG. 2), such that the eccentric rod 12 rotates eccentrically, driving the trigger disc 20 to generate displacement in relation to the safety lever. Next, the knob 13 is relaxed for flexible reset, thereby completing the switching action. In the actual operation, the nailer must be put down or reversed first, and then the knob 13 is manually held and pulled out to allow for rotation and subsequent relaxation. The sequence is inconvenient. Also, the manual control area of knob 13 is limited to the space of the trigger, making it impossible to provide more desirable operation and control of the knob 13.
Referring to FIG. 3, another typical switching mechanism comprises a rotating shaft 30, two springs 31 and two press buttons 32. The rotating shaft 30 is mounted within the trigger 33, and two press buttons 32 are oppositely screwed into a slide shaft 301 at both sides of rotating shaft 30. Two press buttons 32 shift flexibly outwards due to the support of spring 31, so snapper flanges 321 outside of two press buttons 32 snap into spacing groove 331 opposite the trigger 33. If the rotating shaft 30 and trigger disc 34 are to be shifted, as shown in FIG. 4, the operator must press internally two press buttons 32 with two fingers, such that the snapper flange 321 is disengaged from the spacing groove 331. So, it becomes possible to push smoothly the press button 32 and drive the rotating shaft 30. In actual operation, inconsistent manual pressure may lead to asynchronous disengagement and subsequent jamming, and the complex construction of this switching mechanism may bring about more manufacturing cost and time consuming assembly.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.
To this end, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.